G-GC type cable

[Calamar]

Is it possible to install type G-GC cable underground in conduit? If so, how would one go about derating?

 

[tom baker]

Start with Table 400.4 look under Use.

 

[augie47]

400.12 Uses Not Permitted. Unless specifically permitted in 400.10, flexible cables, flexible cord sets, and power supply
cords shall not be used for the following:

(6) Where installed in raceways, except as otherwise permitted
in this Code

 

[tom baker]

Is this a mine application? Are you subject to the NEC?

 

[Calamar]

This is a mine application. We are trying to devise a pathway across an active haul road.

 

[augie47]

Likely not NEC but MSHA as tom noted in which case my answer is invalid.

 

[tom baker]

Portable cable, such as your type is allowed in conduit in industrial locations, but the type g cable is not allowed in a wet location. Any conduit underground is a wet location.
Perhaps you could install in a sleeve, pile rock over it, need to make sure it drains. Is this allowed under MSHA, I do not know.

 

[Jraef]

Portable cable, such as your type is allowed in conduit in industrial locations, but the type g cable is not allowed in a wet location. Any conduit underground is a wet location.
Perhaps you could install in a sleeve, pile rock over it, need to make sure it drains. Is this allowed under MSHA, I do not know.

SOP in gravel pits is to dig a 2' deep trench across the road, put down a layer of sand, lay the cable and put a half-pipe over it, then bury it again. I never once had an MSHA inspector question that. If you lay it on the ground unprotected in an area that normally should not get any traffic but might, , they tag it every time. I should note though that we never tried using Type G cable, it was always Type W.

 

[paulengr]

MSHA requires NEC for coal mines for only one section from the 1976 edition. All the part 56 electrical codes, all 2 pages, are your legal requirements. In the scope of NEC it specifically exempts mines.

It is a design standard only, not legally binding at all. You are free to use or ignore.

Type G is a NEMA standard not UL so a lot of UL stuff doesn’t apply. G, W, and SHD are basically general purpose mine duty cables. I can’t imagine why anything would suggest it’s not wet location.

Your conduit is not conduit in this application. It’s just physical protection. Just be aware since you are going “off the grid” you will need to pay close attention to ampacity and NEC is not your friend when it comes to burial.

Might also want to look at class 50-56 ductile iron pipe. 3 times stronger than any conduit and cheap. Designed specifically for road crossings. Standard is from DIPRA.